Diagnosis of appendicitis in the third trimester of gestation: Case report and review of the literature

Abstract

Objective: To report the case of a woman in the third trimester of pregnancy diagnosed with perforated acute appendicitis and secondary generalised peritonitis; and to review the published literature on the usefulness of diagnostic imaging as part of the workup for this condition during the second half of pregnancy. Materials and methods: We present the case of a 29-year-old patient, gravida 3 para 2, referred to a high complexity institution at 35.2 weeks of gestation with a diagnostic impression of pre-term labour. The patient was taken to laparotomy after remaining under observation for 20 hours of observation, with a diagnosis of abdominal pain and acute appendicitis, and was found to have perforated appendicitis with secondary peritonitis. Post-operatively, the patient developed surgical site infection and premature labour, leading to preterm delivery with satisfactory maternal and perinatal outcome. A search for articles published in English or Spanish over the past 20 years was conducted in the Up to date, Medline vía PubMed and Science Direct databases using MeSH terms "Pregnancy," "Peritonitis," "Appendicitis", "Perforated Appendicitis," "Ultrasonic Diagnosis," "Magnetic Resonance Imaging," "Computed Tomography." Results: Overall, 20 titles directly related to the use of diagnostic imaging in pregnant women with suspected appendicitis were identified. Ultrasound is the first option used for diagnosis, but its diagnostic accuracy during the second and third trimesters is limited because, frequently, it is not possible to visualise the appendix. Sensitivity varies between 46% and 63%, and specificity between 80% and 100%. Nuclear magnetic resonance has better operational performance, with sensitivity ranging between 60% and 100%, and specificity ranging between 95% and 100%, although it is more expensive and has access limitations. Conclusions: The diagnosis of acute appendicitis in pregnancy is challenging. Nuclear magnetic resonance would be more useful than ultrasound for diagnosis during the second and third trimesters.